Lesion crossing shock wave catheter

Abstract

The present invention provides a catheter for treating occlusions in blood vessels. An exemplary catheter for treating occlusions in blood vessels comprises a tubular inner member including a base segment with a first lumen defining a fluid inlet port, and a second lumen defining a fluid outlet port. An extension segment is distal to the base segment. The extension segment has a reduced cross-section. An emitter assembly includes a first insulated wire extending through the second lumen and a second insulated wire, and a conductive sheath wrapped circumferentially around the first insulated wire, the second insulated wire, and the extension segment. A cap or balloon is sealably attached to the distal end of the catheter and surrounds the emitter assembly, said cap or balloon being fillable with conductive fluid.

The invention claimed is: 
     
       1. A catheter for treating occlusions in blood vessels comprising:
 a tubular inner member having a proximal portion with a first diameter and a distal end portion having a second diameter smaller than the first diameter, with the proximal portion of the inner member including four circumferentially positioned flutes, each of the circumferentially positioned flutes receiving one of four tubes, 
 a first wire located in a first tube of the four tubes and extending distally beyond the first tube; 
 a second wire located in a second tube of the four tubes and extending distally beyond the second tube; 
 a third tube of the four tubes connectable to a source of conductive fluid; 
 a fourth tube of the four tubes configured to define a return path for the conductive fluid; 
 a cylindrical insulation sheath positioned around the distal portion of the inner member and radially inside the distal ends of the first and second wires; 
 a cylindrical conductive sheath surrounding the distal ends of the first and second wires and defining two electrode pairs; 
 a sheath surrounding the proximal portion of the inner member; and 
 a flexible cap surrounding the conductive sheath and a distal tip of the catheter. 
 
     
     
       2. The catheter of  claim 1  wherein the inner member is formed from a single extrusion. 
     
     
       3. The catheter of  claim 1  wherein the fourth tube is connectable to a source of suction. 
     
     
       4. The catheter of  claim 1  wherein the sheath surrounding the proximal portion of the inner member is a wire braid. 
     
     
       5. The catheter of  claim 1  wherein the inner member further includes a central guidewire lumen. 
     
     
       6. The catheter of  claim 1 , comprising a cylindrical jacket surrounding the first tube, the second tube, the third tube, and the fourth tube. 
     
     
       7. The catheter of  claim 1 , wherein the cylindrical insulation sheath comprises a constant diameter distal portion and a tapered proximal portion. 
     
     
       8. The catheter of  claim 1 , wherein the distal end of the first wire is uninsulated and is separated from the cylindrical conductive sheath by a first gap. 
     
     
       9. The catheter of  claim 8 , wherein the distal end of the second wire is uninsulated and is separated from the cylindrical conductive sheath by a second gap. 
     
     
       10. The catheter of  claim 9 , wherein when a voltage is applied to the proximal ends of the first wire and the second wire, current jumps the first gap between the uninsulated distal end of the first wire and the cylindrical conductive sheath to generate a first shock wave, and jumps the second gap between the uninsulated distal end of the second wire and the cylindrical conductive sheath to generate a second shock wave.